Anyone ever fit one of these.. are they hard fit.. did they make a difference... is the exhust sytem on a beams celica the same as an ordonary celica....

decat pipes just go in place of you secondary cat and are the same length and should just bolt right in.

does it make much of a horsepower difference

they say 5-10 bhp

is it just a straight pipe swap or is there's any sensors down there that could screw things up

no you might gain like 1 hp on the dyno i dunno its not gonna be noticible. and no there are no sensors that itll bess up but id your really looking for gains get a new header and eliminate the primary cat.